Mechanism for metal-working machines



I w. J. T. MCLEAN MECHANISM FOR METAL WORKING MACHINES Filed May a, 1925 4 Sheets-Sheet 1 July 13,1926. 1,592,378

W. J. T. MQLEAN' MECHANISM FOR METAL WORKING MACHINES Filed May 5; i925 4 Sheets-Shet 2 Maw Jam yam 7 (94% max Jul 13 192 1,592,378

W. J. T. M LEAN MECHANISM FOR METAL WORKING MACHINES Filed May a, 1925 4 Sheets-Sheet 5 Jul 13,1926. 1,592,378

W. J. T. MCLEAN uacrmmsm FOR. METAL WORKING MACHINES Filed May a, 1925 I -4 Sheets$heet 4 wda; 7W 7W A' AM Patented July 13, 1926.

UNITED STATES PATENT OFFICE.

WALTER JAMES THOMAS MCLEAN, 0F ELTI-IAM, VICTORIA, AUSTRALIA, ASSIGNOR TO THE M. RAIL ANCHOR LIMITED, OF MELBOURNE, AUSTRALIA.

MECHANISM FOR METAL-WORKING MACHINES.

Application filed May 8, 1925, Serial No.

My invention relates to improvements in mechanism for metal-working machines for bending, punching, pressing, upsetting, cutting, or shearing, and may include in combination subsidiary means for rolling; and

' the objects of my improvements are, firstly,

to provide mechanism such that a shorter and more powerful stroke than usual may be obtained with the same expenditure of power and, secondly, to provide mechanism of compact and relatively light construction by which the above specified operations may be performed. v

I attain these objects by the mechanism illustrated in the accompanying drawing, in which- Fig. 1 is a side elevation of the machine, part of the automatic clamping means being omitted for the sake of clearnessj Fig. 2 is a plan of the machine;

Fig. 3 is an end elevation of the same;

' Fig. 1 is an enlarged view showing the contour of the face of a roller;

Fig. 5 is a section through 5-5 on Fig.

" 6 and shows the'rack andassociated parts;

Fig. 6 is a section through 6-6 on Fig. 5;

Fig. 7 is an enlarged view of the forked bracket nipping a chain;

Fig. 8 is an elevation of the same;

Fig. 9 is a sectional elevation through 99 on Fig. 5 showing the pawls in engagement with the rack;

Fig. 10 is a plan of a modification of the machine which is provided with a rack at each end; i

Fig. 11 is an enlarged view showing a rack-faced crank-arm in engagement with the endof the main shaft;

Fig. 12 is a side elevation of the same showing also a connecting rod'and tool-carrier.

A sliding tool-carrier in the form of a rack block 1 carries the tool 2 or other actuated part and is progressively driven forward by a sliding drive-block 3 which is pivoted to the end of a connecting rod 4 driven by an eccentric 5 mounted on the main shaft 6. The forward end of the drive-block is provided with a pawl 7 which engages a tooth such as 9 011 the rack 10 during the forward stroke of the connecting rod and slides rearwardly over the'next adjacent tooth 11 during the reverse stroke of the connecting rod so that, for example, if the stroke of the connecting rod is 1 inch 28,869, and in Australia October 6, 19 24:.

and the distance between the adjacent teeth on the rack-block is also 1 inch. the rackblock will carry the tool forwardly 1 inch for each stroke of the connecting rod and will continue to carry it forward stroke by stroke until thepawl has reached the last tooth. The rack-block and tool may be withdrawn by raising the first pawl 7 out of operative position and lowering a sec ond pawl 12 which engages reversely-directed teeth 13 on the rack-block so that each stroke of the connecting rod withdraws the rack 1 inch. This withdrawal movement may be used either for returning the mechanism to its starting position or forroperafive purposes. By this means a machine of relatively light construction may be adapted to exert a short powerful stroke which is built up progressively step-by-step so as to obtain an equally good or better result than a machine of much heavier construction; If a step-by-step movement is not desiredin any particular operation, both pawls may be engaged and the rack-block will then be withdrawn during the rearward stroke of the connecting rod to the same extent as it Normally the rack is provided with twelve (12) teeth and the stroke of the connecting rod is 1 inch,but obviously the number of teethmaybe varied and the length of stroke and distance between the adjacent teeth may also be varied as desired. The machineis mounted on a suitable base such as on longitudinal girders 14L suitably braced and connected together by cross girders 1 1 and the ends. of the girders 14 are adapted to support the work-holder 15, being provided with bolt holes 16. The sides of the rack-blocks willbe bevelled laterally at 17 and side guide-plates 18, which are corre spondingly bevelled at 19, will be bolted to the girder frame. To adjust these guideplates for wear they maybe planed as on 'necting rod being bifurcated so that it may be driven by lateral extensions 23 of the eccentric on the main shaft. ifhe head of the first connecting rod is accommodated within the bifurcation of the second connecting rod. The smaller end ofthe second conne ting rod is pivotally connected ier to a second drive-block 3 which co-ope c nd rack-block 1 (Fig. which with its associated parts is similar to the rack-block l and its associated parts, or pref ably to a second drive-block (Fig. 2) v. ch is cor.- nected to a sliding tool-earner by meat;

L of a partly counter-balanced i nationally operated wedge 26. T. on, e slides downwardly between the second flill'G-biO-Cli and the sliding tool-carrier (hiring the return stroke of the second connecting rod so that the sliding tool-carrier is forced rearwardly step-by-step by the motion of the second connecting rod. The wedge is provided with lateral lugs 27 which are accommodated in vertical recesses 28 in the sliding driveblocl: and tool-carrier so that the raising of the wedge by a slight pressure on the counter weights 29 causes the sliding tool-carrier to be withdrawn progressively. The wedge is almostcounter-balanced by means of counter weights and a chain (Fig. 3) passing over pulleys 81. A limit stop 32 may be provided to limit the movement of the wedge. In addition the wedge can be held stationary in any position by nipping the chain in a forked bracket 32 (Figs. 1, 3, 7 and 8). By each of these means a definite stroke may be obtained as desired. Very line adjnstment of the stroke may be obtained by the use of this wedge. A second workholdcr 15 may be bolted in position through bolt holes 16 The main shaft may be extended laterally, preferably on the side away from the fly wheel and driving pulleys, and may be provided with an eccentric actuating a vertical connecting rod 31- operating a tool-holder or the like 34*, more especially for smaller work. The main shaft may be further extended and provided with a roller 35 against which a lower roller for rolling hot iron or for welding may be brought to bear by means of a spring returned pedal-lever 3. and linkwork 3e. bviously the rollers may be of any desired contour, one form- 36* of which is shown in Fig. l. This lateral extension of the shaft may be slotted (li2lll'l0 trally on its end, the inner face of this slot 39 being preferably formed as a rack d0 so that a rack-faced crank-arm 4-1 11) may be secured to it in predetermined position by a screw 41 To one end of this crankarm is pivoted a connecting rod l adapted to operate a sliding tool-carrier a (Fig. 12) fitted at the side of the n'iachine. By varying the position of the crank-arm in relation to the main shaft the stroke of this latter connecting rod may be varied as desired.

By the provision of.a third longitudinal girder (not shown), the front and rear ope obvious.

Automatic clamping means, for holding the work 'a position durin the operation of the tool, comprises a slidg wedge st which is attached to a connecting rod 45 which re ceives its motion from a cam 46 which is keyed to the shaft 6. Obviously a duplicate set of clamping means could be placed on the opposite side of the eccentrics 23. In operation, the sliding wedge 44 actuatcs the aws of a work-holder 15. A spring 47 keeps the connecting rod 45 in contact with the cam d6.

1 claim- 1. The combination in mechanism for metal-working machines, of a horizontally reciprocating drive-block, a shaft, driving means actuated by the shaft, a connecting rod linking the drive-block to the driving means, with a pawl on the forward end of the drive-block, a sliding tool-carrier, a rack on the tool-carrier engaging the pawl progressively tooth-by-tooth; a second pawl on the drive-block, a second rack laterally contiguous to the first rack on the toolcarrier, a reversely-directed set of teeth on the second racl': engaging the second pawl progressively tooth-by-tooth when the sec- 0nd pawl is lowered; and work-holding means.

2. The combination in mechanism for metal-working machines, of a reciprocating drive-block, a shaft, aneccentric on the shaft, a connecting rod linking the eccentric to the driveblock with a pawl on the forward end of the driver-block, a sliding tool-carrier, a rack on the tool-carrier engaging the said pawl progressively tooth-by-tooth, a second pawl on the drive-block, a second rack on the tool-carrier, a reversely-di'rected set of teeth on the second rack engaging the second pawl progressively tooth-by-tooth when the second pawl is lowered work-holding means; a reversely-directed second connecting rod, a bifurcated head on the second connecting rod, lateral extensions of the said eccentric driving the said bifurcated head, a second reciprocating drive-block pivoted to the said connecting rod, a second sliding tool-carrier, means connecting the second drive-block to the secondtool-carrier, and a second work-holding means associated with said second tool-carrier.

3. The combination in mechanism for metal-working machines, of areciprocating drive-block, a shaft, an eccentric on the shaft, a' connecting rod linking the eccentric to the drive-block, with a pawl on the forward end of the drive-block, a sliding. toolcarrier, a rack on the tool-carrier engaging rative slides could be dupli ated as will be lOO means; a reversely-directed second connecting rod, a bifurcated head on the second connecting rod, lateral extensions of the said eccentric driving the said bifurcated head, a reciprocating drive-block pivoted to the second connecting rod, a second sliding toolcarrier, at gravitationally-operated wedge sliding vertically between the second drive-' block and its tool-carrier, lateral lugs on the wedge slidably engaging recesses on the said drive-block and tool-carrier; and work holding means.

4. The combination in mechanism for metal-working machines, of a shaft, driving means on the shaft, a t-ool carrier driven progressively step-by-step from the shaft, withan extension onthe shaft, an additional eccentric on the said extension, a vertical connecting rod driven by the said additional eccentric, a sliding tool-carrier pivoted to the said vertical connecting rod, a roller mounted on the said extension, a second rollor co-operating with the first roller, a rack faced slot on the end of the said extension, a rack-faced crank arni engaging the said slot, a connecting rod pivoted to said crankarmand' a sliding tool-carrier pivoted to said connecting rod; a rotary cam, a slidin wedge operated by the rotary cam, and work-holdii'ig jaws actuated by the sliding wedge.

In testimony whereof I aflix my signature.

WALTER JAMES moms McLEAN. 

